1. Department of Public Health; Yonsei University Graduate School; Seoul Republic of Korea
2. Department of Epidemiology and Health Promotion; Institute for Health Promotion, Graduate School of Public Health, Yonsei University; Seoul Republic of Korea
3. Department of Epidemiology; Bloomberg School of Public Health, Johns Hopkins University; Baltimore MD
4. Department of Preventive Medicine; Keck School of Medicine, Institute for Global Health, University of Southern California; Los Angeles CA